The Appalachian region has a population of 23 million residing in 420 counties and 13 states. Forty-two percent of the region's population is rural. Compared to other regions, people living in Appalachia were reported to face a heavier burden from chronic diseases such as obesity, diabetes, and heart disease. The proportions of obese high school students in Southern Appalachia are among the highest in the nation. Health risk habits including unhealthy eating and physical inactivity are often established during adolescence and may contribute significantly to this chronic disease disparity. Although adolescent obesity is an urgent public health issue, effective interventions are few. Therefore, we propose to test an academia-community partnership approach using college students as facilitators to prevent obesity among adolescents. The long-term goal is to establish an effective academia-community partnership program to address adolescent obesity disparity in Southern Appalachia. The specific aims are: 1) To develop a peer- based health education program focusing on establishing positive peer norms and supportive peer relationships toward healthy eating and physical activity among high school students, 2) To test the efficacy of the program, and 3) To explore the mechanisms underlying the program. Twelve (six per each semester) undergraduates at East Tennessee State University will be trained to conduct an eleven-week peer-based health education program as peer facilitators. A cluster-randomized trial design will be used and 6 rural high schools will be randomly assigned to the intervention and control groups. Approximately 1440 adolescents will be included as study subjects. Body mass index (BMI) percentile, dietary behavior, and physical activity among the study subjects will be assessed pre-intervention, at the end of the intervention, and 12 months post-intervention. Mean levels and/or prevalence of differences in the assessments (BMI percentile, obesity status, eating behavior, and physical activity) will be compared between the intervention and control group at the 3 time points (pre-intervention, end of intervention, and 12 months post-intervention). Peer group norms, body image, supportive peer relationships, role modeling, behavioral control/self-efficacy, attitudes, and intentions toward healthy eating and physical activity will be assessed pre-intervention, at the end of the intervention, and 12 months post-intervention. The roles of these factors as mediators of the intervention in modifying adolescents' eating and physical activity behaviors, as well as, body mass index will be examined. This proposed study will provide an important evaluation of an academia-community partnership using college students as facilitators to address adolescent obesity disparity in Southern Appalachia. If proven effective, the proposed program can meet the critical community needs for adolescent obesity prevention by engaging higher education institutes and students in service and fostering within them an ethic of civic responsibility. The program will be easily transferable from research to action without substantial additional resources and will be a sustainable win-win program for both the community and the academy. 1 PUBLIC HEALTH RELEVANCE: This proposed study will provide an important evaluation of a peer-based program. If proven effective, the proposed program can meet the critical community needs for adolescent obesity prevention by engaging higher education students in service and fostering within them an ethic of civic responsibility. A community-campus partnership with this proven program as the core can be built to address adolescent obesity in Southern Appalachia. It would be a sustainable win- win program for both the community and the academy. .